An assessment framework for underground construction methods in the pre-construction stage: a technical perspective

The selection of an appropriate underground construction method plays a crucial role during the pre-construction phase as it must consider various aspects, such as safety, technical feasibility, and cost-effectiveness. However, there is still a lack of technical assessments for selecting suitable underground construction methods in the research field. Therefore, this study aims to build an assessment model to technically assess such methods in the pre-construction stage. Firstly, technical assessment factors were obtained from literature reviews, expert consultations and survey results. Factor analysis was performed to reveal the underlying significance of each factor. The Fuzzy Analytic Hierarchy Process (Fuzzy AHP) model was then constructed to assess the relative importance of each factor. Finally, the assessment model was validated by seeking experts' opinions on its performance in a practical project. The study resulted in a Fuzzy AHP model established from a list of 8 groups of factors with 35 refined factors, covering many aspects from documents and resources to geology and hydrology. The validation results demonstrated the model's effectiveness in assisting contractors to make informed decisions. This study has contributed to construction literature by introducing a novel framework for underground construction methods, offering a practical tool for pre-construction planning and decision-making.